The present invention relates to apparatus for providing a dust free environment in the filling and discharge of containers. More particularly, the present invention relates to a slide gate and dust cover operator and seal assembly for use in providing a sealing arrangement for containers of solid materials such as dry powder or tablets.
Previous apparatus for providing a dust free environment for containers is described in the following U.S. Pat. Nos. 3,354,918 to Coleman; 3,729,121 to Cannon; 3,985,245 to Schulte; 4,249,679 to Dillman; 4,428,504 to Bassett et al.; 4,491,253 to Coleman; and 4,830,233 to Thelen et al.
By the present invention, there is provided an improved sealing arrangement which involves a dual seal which seals directly against the gate assembly. In addition, the present invention provides for the introduction of air between the inner and outer seal to prevent contaminants from reaching the product.